Acoustic feedback conditions normally occur when two communication devices operating on the same frequency are close enough to each other. A typical example of this problem occurs when a police officer, who carries a portable radio, also has a mobile radio in his police car. Upon entering the police car with his portable radio turned on, acoustic feedback between the the portable and mobile sometimes occurs when the user begins using the mobile radio. The noise and disruption that is caused by the acoustic feedback forces the police officer normally to shut off his portable radio whenever the officer is inside his car. The problem with having to turn off the portable radio is that upon leaving the police car, the officer must remember to turn his portable radio back on, or else important communications may go unheard.
Given the major risk of losing valuable conversations which can sometimes be of a life threatening nature, a better way of controlling the muting of a radio is required when acoustic feedback is a problem.